The present invention relates to a double cassette tape player for use with a telephone set in which a pair of tape cassettes are alternately operated.
In general, in a tape player of a double cassette type used in a telephone set, the tape cassettes are alternately driven. This is because, for example, one of the tape cassettes is used to record outgoing messages to be sent, whereas the other one of the tape cassettes is utilized to record incoming messages from communicating partners and to playback the recorded messages later.
FIG. 7 is a schematic diagram showing a driving unit of such a conventional double cassette tape player for use with a telephone set.
The system of FIG. 7 includes micro-sized cassette halves Ca and Cb. These two cassettes Ca-Cb are mounted on reel plates Ra and Rb in two cassette mounting sections, respectively on a chassis 1a. In the cassette mounting section, there are further respectively disposed capstans Ka-Kb and pinch rollers Pa-Pb. The respective cassette mounting sections include separate magnetic heads Ha and Hb.
When the double cassette tape player of this kind is used in a telephone set to send and receive messages while the user of the telephone set is absent, the cassette mounting sections are not driven at the same time, namely, each cassette mounting section is driven alternately. Furthermore, in general, only one amplifier circuit is provided. As a consequence, in order to balance the tone volume of the playback sound of each tape cassette thus mounted, two magnetic heads Ha and Hb must be selected so that the difference of the characteristics are minimized between the magnetic heads Ha and Hb.
Consequently, the operation to select the magnetic heads becomes complicated, which leads to a disadvantage that the assembly and adjustment thereof are attended with difficulties. Moreover, since two magnetic heads are disposed in the driving unit of a tape player, the number of parts becomes greater and hence the production cost will be increased.